Actuator valves are well known and have been in use for many years and have performed in a satisfactory manner. An example of such an actuator valve is set forth in U.S. Pat. No. 3,814,376. This patent describes a linear motion two position valve that utilizes both permanent and electromagnets to provide fast response and low power consumption with magnetic latching in both positions. This is accomplished by utilizing a linear motion armature that also serves as the movable valve member, providing a permanent magnet to latch the armature in either valve open or valve closed position, and using a pair of like wound solenoid coils for moving the armature from one position to the other. The coils are momentarily energized with current flowing in one direction to move the armature from a given one of the two positions to the other, and momentarily energized with current flowing in the opposite direction to move the armature in the opposite direction. The greater portion of the flux from the permanent magnet moves in one axial direction through the armature when the armature is in one of the two positions for latching the armature in that position and is switched in direction through the armature when the armature is in its other position for latching the armature in such other position. This valve exhibits an exceptionally high latch or holding force to movable mass ratio which provides superb anti-ratting tolerances during the high vibration and shock environments present in the launch of space launch rockets and the satellites launched into space by such rockets. Unfortunately, this valve and other similar valves have limitations.
The actuator valve disclosed in this patent has been manufactured and used and has been shown to operate very efficiently at pressures up to 500 psig, and has proven to be producible in miniature and micro sizes as light as 8 gram. However, there are numerous industrial and aerospace valve applications that require operating pressures of 5,000 psig and greater and large flow capacities. However the actuator valve disclosed in this patent becomes heavy and bulky when designed to operate at these higher pressures and flow capacities. Moreover, the coils require high electrical current and power. Large weight, size and power are detrimental in aircraft and especially in space flight applications, where weight, size and power must be kept to an absolute minimum. Another limitation of the actuator valve disclosed in this patent is that it can only be used in “latching valve” applications, e.g., where the valve remains in the last commanded position without electrical power.
There are many actuator valve applications where it is necessary for the valve to always return to the closed position in the event of electrical power loss, which is often called a “normally-closed” or “fail safe-closed” valve. There are even actuator valve applications where its necessary for the valve to always return to the open position when power is lost, which is called a “normally-open” valve.
There are still other valve applications where it is necessary to electrically modulate the valve to partially open positions to provide a controllable variable fluid flow throttling function. These low pressure, small flow capacity, and operating mode limitations associated with actuator valve disclosed in this patent and other similar actuator valves have been overcome with the present multi-force actuator valve invention. The present multi-force actuator valve invention overcomes the inability of the prior art actuator valves to effectively operate at high pressures and at high flow capacities as well as the weight and bulkiness and high electrical current and power problems associated with prior art actuator valves that attempt to handle high pressures and high flow capacities. The present multi-force actuator valve invention overcomes the inability of the prior art actuator valves to operate in other modes than the latching mode where the valve remains in the last commanded position without electrical power.
The multi-force actuator valve invention provides substantially improvements to prior art actuator valves and can effectively be used to operate a fluid control valve or other such valve. The multi-force actuator valve invention is a substantial improvement over prior art latching actuator valves and has increased energy utilization efficiency. With the present invention, mechanical energy stored in mechanical springs and the like is added to the electromagnetic actuation force to improve latch valve performance capability at higher operating pressures and flow rates, while achieving smaller valve size, lower weight and reduced power consumption. The present invention also enables the valve structure to operate in a plurality of modes including normally-closed, normally-open and modulating modes.